/Engine/Source/Runtime/Core/Public/Templates/UniquePtr.h
Assignment operator for rvalues of other (usually derived) types
template<typename OtherT, typename OtherDeleter, typename> [TUniquePtr](API\Runtime\Core\Templates\TUniquePtr) & operator= ( [TUniquePtr](API\Runtime\Core\Templates\TUniquePtr)< OtherT, OtherDeleter > && Other )